TIU not seeing active engines on VAR 1 track

I have the same problem as you so, so you are not alone. In fact, not only are engines not recognized, the watchdog signal is never received on VAR1 or VAR2. I gave up and  now use my TIU in passive mode, using a Legacy Powermaster to set and control voltage. Now everything works fine. 

Weird... Obviously no dcs signal present in var mode   Is it possible you have a reversed connection (red always  to center rail)

Try setting the var to fixed mode with Menu/System/ dcs set up. select the var channel and hit FXD. (to put the channel back in var mode hit FXD again) Any luck?

While  there  make sure the dcs signal is turned on to all channels with  AON...

You can go to DCS and hit AON which turns on ALL DCS Signals and see if that works.  But it you have good signal in F1, 2 and V2, then most likely you lost signal transformer on V1.  That is repairable.  E-mail in profile. G

GregR posted:

I have the same problem as you so, so you are not alone. In fact, not only are engines not recognized, the watchdog signal is never received on VAR1 or VAR2. I gave up and  now use my TIU in passive mode, using a Legacy Powermaster to set and control voltage. Now everything works fine. 

If VAR 1 and 2 work in Passive mode there is no reason it would not going through VAR 1/2.  IF you mean you are using Fix in passive.  Try my recommendation above, otherwise you have a hardware fault also.  Again repairable.  IF less than 1 year old send in for warranty repair.  G

Greg has it right. Ensure that the wires from Variable out are not reversed.